28
c) Terminal block BC2 Command
The units have the BC2 terminal block for interconnection of commands and signals from the control. Pay attention to the
voltage diff erence between them. For details, go to the complete wiring diagram of the unit. Find a descriptive table of
terminal block BC2 below.
The control mounted on the front panel of the unit is low DC voltage and does not require batteries to store user
settings in memory.
NOTE
The communication mode used is the RS-485 COM pattern (See fi gure 20). Use a twisted-pair cable with shield for
communication A and B. Do not exceed the length in 120 meters to avoid the transmission rate be aff ected and
voltage drop. Use cable 2 x 0.5mm 2 for thermostat power 12VDC and GND.
IMPORTANT
HAZARD OF DAMAGE TO THE UNIT
Failure to observe this precaution could result in equipment damage or malfunction. Improper wiring or installation can
damage the control. Make sure the wiring / connection is correct before turning on the power.
CAUTION
TERMINALS
DESCRIPTION
1,2
ULWT – Unit Water Outlet Temperature Sensor
3,4
RLWT – System Water Inlet Temperature Sensor - for master units
3,4
RLWT – System Water Outlet Temperature Sensor - for slave units
5,6
DPS - Pressure switch contact, pressure diff erential between inlet and outlet water
7,8,9
WFC - Water fl ow sensor return and supply
10,11,12
WV - 24VAC - Power and command of water valve On / Off
13,14
WP - 24VAC - Command of the water pump
15,16
Dry contact to turn on and off the system remotely - for master units only
17,18
220VAC – Remote alarm signal (for Inverter systems only)
4. Instalation (cont.)
